This invention relates to RFID tags for use in identifying packages and the contents thereof. It is currently known to use RFID tags for purposes of identifying packages, containers, and the like. Such identification TAGS can provide the user of an RFID reading device with data which can be correlated to information about the contents of a container. The information may be stored in digital form as part of the RFID response code, or alternately may be maintained in a computer database with a correlation to the RFID identification sent by the tag in response to an interrogation signal. FIG. 1 shows an arrangement of containers 20 having RFID tags 22. The stack of containers 20 may be arranged, for example, in a warehouse or on a pallet for shipment. In connection with identifying the content of the containers or locating a particular container, it is possible to use an RFID interrogator to interrogate the tags 22 on the face layer of boxes 20. However, depending on the contents of the boxes and the number of layers of boxes in the stack, no assurance can be given concerning the interrogation of tags at the center or rear of the stack.
It is an object of the present invention to provide packaging containers which enable an RFID signal to penetrate a stack of containers so that containers located at the center or rear of the stack can be interrogated without moving the containers arranged in the front of the stack.